27 CFR §19.483

1. (a)Basic requirements. A proprietor must place the marks prescribed by this subpart on cases, encased containers, and packages of spirits and denatured spirits so that they are:
   1. (1)Of adequate size to be easily read;
   2. (2)Of a color in distinct contrast to the color of the background;
   3. (3)Legible; and
   4. (4)Durably affixed.
2. (b)Use of labels. A proprietor may use labels as the means for applying prescribed marks if the labels meet the requirements of paragraph (a) of this section.
3. (c)Location. A proprietor must place the prescribed marks on one side of the case or encased container, or on the head of the package.